|The two colourless faceted gemstones pictured above weigh 0.41 ct. and 0.19 ct. are natural bromellite.
It is thermally conductive, as you can see in the above photo. The black needle is over the i in the diamond name on the display.
The refractive index is 1.718-1.732. Birefrengence is 0.014. A uniaxial interference figure is visible in the polariscope. A weak orange colour is visible under the SWUV lamp. No absorption bands are visible with the hand spectroscope.
One colourless bromellite crystal was found near Gilimala, Sri Lanka in March 1999. It was cut into 17 faceted stones the largest weighing 2.80 ct. the next biggest was 1.90 ct, the next was 0.68 ct. The remaining 14 cut stones were all below 0.50ct in.weight.
The pictured 0.19 ct. faceted stone was from the same crystal and was a gift to me from Mr. Palitha Gunasekera of Ratnapura, Sri Lanka. It was Mr. Gunasekara who purchased this stone, and recognizing it's uniqueness, sent it to the Gemological Institute of America for advanced testing.
The 0.41 ct stone, pictured above, I purchased from Mr. Gunasekara in March 2004. It was the last stone of the original lot remaining in Sri Lanka.
It is believed this is the only Sri Lankan crystal found so far. Since that time many people have been looking but no one has found another bromellite in Sri Lanka. I don't expect to ever obtain another.
Bromellite in very small sizes (to small to cut) has been found in Sweden as well as in the Ural mountain area of Russia.
Gems & Gemology has described the three largest stones cut from this crystal with a colour photo as well as four bromellite internal inclusion photos (natural and synthetic) in the Fall 2002 issue, V.38 N.3 pages 250-251.
Bromellite is chemically BeO. It's hardness is 9. Specific gravity is 3.01-3.03. The crystal system is hexagonal. Because of the high beryllium content (about 36%) the dust and fumes can be toxic, when it is being cut or formed.
The inclusion photo above taken of a 0.41 ct bromellite (70x), shows some 2 phase inclusions as well as some colourless pointed inclusions . Other colourless inclusions seem to display crystal faces.
A synthetic bromellite crystal weight 16.54 ct. Note the wire for hanging the seed in the flux solution. Probably grown in California in the 1960s. A gift from Dr. Manfred Burianek of the Institute of Krystallography, University of Cologne, Germany.